A wireless mesh network has architecture in which a plurality of movable wireless nodes is connected in a mesh form. A node of the wireless mesh network, which is a node configuring a mesh network, may perform inter-node communication. Each node has a function of transmitting or relaying data for inter-node communication and needs to have a function of setting a path for multi hop transmission. The mesh network has architecture in which all the nodes are locally connected or may be operated in architecture in which all the nodes are locally separated. Mesh nodes operated by being connected with each other in each network are referred to as a mesh group. The mesh group may be dynamically separated or merged by the mesh nodes having mobility.
Since the wireless mesh network can implement multi hop transmission, communication cannot be made due to a malicious node transmitting wrong information or wireless data transmission between the mesh nodes can be monitored. Therefore, authentication of each node and encryption of data transmitted and received between nodes are essentially required.
In the wireless mesh network according to the related art, as an authentication method between the nodes, a central authentication method using an authentication server has been mainly used.
In the central authentication method, the authentication server having information on all the nodes within the mesh network are present and there is a need to access the authentication server each time the node is authenticated. When an authentication requesting node is not directly connected with the authentication server, intermediate nodes relay between the authentication requesting node and the authentication server to perform an authentication procedure. Therefore, when several nodes simultaneously request authentication, an overload may occur in a path to the authentication server and a lot of delay may occur during the authentication procedure.
Even though the load impedance is matched with the impedance of a circuit to which the plurality of sources is connected, the load impedance is not matched with each source, such that the available electric power of each source is not used maximally.